Autofocus While shopping you'll read a lot about different autofocus systems. The most common thing you'll find is that some systems have more "points" than others. This simply means that they can detect a subject in more parts of the frame. More points are better, but the speed of the autofocus mechanism is equally important. Also, DSLRs don't have the shutter lag that many point and shoot cameras have. Still, focusing a DSLR requires pressing the shutter button halfway and can take varying amounts of time on different cameras. If you can get a hands-on experience with a DSLR before you buy, check the autofocus speed.
Continuous autofocus is a handy feature if you are photographing moving subjects. Some new DSLRs now offer continuous autofocus while shooting video. This is a great feature, but if you're shooting without an external microphone, your video might pick up the sounds of the lens refocusing.
Size A full-size DSLR is larger and heavier than other camera types, so comfort is key. A camera that fits comfortably in one person's hand may be too large or small in someone else's. If size and weight are a serious concern, you may want to consider a compact interchangeable lens camera, which have bodies as small as point-and-shoot cameras.
Dust buster If you think you'll be changing lenses often, look for a DSLR with an internal sensor cleaner. This helps keep your image sensor clean and dust free. If you're using your camera in rugged, outdoor conditions you may still need to manually clean your camera.
File formats DSLRs support raw file formats, which are un-processed files. Raw files offer the most editing flexibility when you open the photo in an image-editing program. However, if the camera is still relatively new, keep in mind that you may need to wait for editing programs from third-parties, such as Adobe and Apple, to support the camera's raw format. DSLRs also support the JPEG format, which all image editors can read, no matter what type of camera takes the image. JPEG uses compression to create smaller file sizes that won't take up as much storage space as raw files, but do not have as good image quality.
Continuous shooting mode If you take photos of sporting events, kids, or any other fast, unpredictable subject, a continuous-shooting (or burst) mode will make a huge difference in your photography. This mode lets you hold down the shutter button to shoot multiple photos in rapid succession. The number of pictures you can record in one burst is determined by your camera's electronics—and in some cases by the type of memory card you have. You may need a more high-speed memory card to take advantage of your camera's fastest shooting rate. If so, be sure to factor that cost into your decision. To be effective, a continuous shooting mode should capture images at least 3 fps (frames per second) or faster at the camera's highest resolution.
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